The present invention relates to a hydrogen engine system, and more particular, to a hydrogen engine system on which a medium for generating hydrogen from organic hydride owing to dehydrogenation is mounted.
In a situation, in which global warming is becoming serious due to carbon dioxide, etc., attention is paid to hydrogen as an energy source, which bears the next generation in place of fossil fuel. It has been studied how to construct those systems for transportation, storage, and feeding of hydrogen, which are essential in using hydrogen as a fuel. That is, hydrogen is gaseous at room temperature and so difficult to store and transport as compared with liquids and solids. Besides, hydrogen is a combustible substance to involve a danger of explosion when mixed with an air at a predetermined mixing ratio. Therefore, as described in, for example, JP-A-2005-126315, it is known that a planar flow passage, a catalyst layer, hydrogen separation means, and a flow port are formed integrally in a dispersed power source and a small-sized, efficient hydrogen storage/feed unit used in automobiles.
Also, as described in, for example, JP-A-2005-147124, it is known that in a system for driving of an engine using hydrogen gases generated from a medium, which generates hydrogen from a conventional, organic hydride owing to dehydrogenation, as a fuel, hydrogen-rich gases are separated from organic hydride (referred to as hydrogenated fuel) and fed to an internal combustion engine such as gasoline engine, diesel engine, hydrogen engine, etc.
The unit described in JP-A-2005-126315 is difficult to generate a large amount of hydrogen gases and so can neither reduce CO2 discharge as far as possible in an engine of an automobile nor discharge CO2. Also, the system described in JP-A-2005-147124 discharges CO2 when gasoline or hydrogenated gasoline is fed as a fuel to an engine.
Further, dehydrogenation of organic hydride such as methylcyclohexane, decalin, etc. is an endothermic reaction (68 kJ/mol) and reaction temperature is as high as 250° C. or higher, so that a whole system becomes large in size since an electric source must be mounted separately when a heater or the like is used to heat a dehydrogenation reactor.